From: Lukas Krickl <lukas@krickl.dev>
Date: Mon, 15 Dec 2025 14:58:22 +0000 (+0100)
Subject: player: Added basic movement
X-Git-Url: https://git.krickl.dev/?a=commitdiff_plain;h=ec753400a021cb90d2aeab102253af0abf30f0fd;p=gbrg%2F.git

player: Added basic movement
---

diff --git a/src/actor.s b/src/actor.s
index d49ee35..5bcf01f 100644
--- a/src/actor.s
+++ b/src/actor.s
@@ -7,10 +7,10 @@
 	;	bits:
 	;     SYYYSXXX
 act_dir_vector:
-.db 0x90 ; SOUTH	
-.db 0x10 ; NORTH
-.db 0x09 ; WEST
-.db 0x01 ; EAST
+.db 0x10 ; SOUTH	
+.db 0x90 ; NORTH
+.db 0x01 ; WEST
+.db 0x09 ; EAST
 	
 	; reverse direction
 act_dir_reverse:
@@ -88,12 +88,72 @@ act_can_move:
 
 	ret
 	
+	; applies a direction vector to the current actor
+	; inputs:
+	;		de: actor
+	;		 b: direction vector (SYYYSXXX)
+act_apply_vec:
+	ld hl, act_pos_y
+	add hl, de
+	
+	ld a, b
+	; extract y direction
+	and a, 0xF0
+	swap a
+
+	; a = y direction
+	push bc
+	push hl
+	call act_apply_pos
+	pop hl
+	pop bc
+
+	inc hl ; hl = x pos
+	
+	ld a, b
+	and a, 0x0F
+	; a = x direction
+	call act_apply_pos
+
+	ret
+	
+	; applies a single position based on its
+	; sign bit
+	; inputs:
+	;		hl: ptr to position 
+	;    a: 0000SNNN -> vector value
+	;	preserves: de
+	; uses hl, bc, af
+act_apply_pos:
+	; check sign
+	bit 3, a
+	jr z, @nosign REL
+
+	and a, 0b00000111
+	ld b, a
+	ld a, [hl]
+
+	sub a, b
+	ld [hl], a
+
+	ret
+@nosign:
+	and a, 0b00000111
+	ld b, [hl]
+
+	add a, b
+	ld [hl], a
+
+	ret
+	
+	
 	; moves the actor forward
 	; does not perform collision checks
 	; inputs:
 	;		de: actor
 act_move_forward:
 	ld hl, act_dir
+	add hl, de ; hl = act_dir
 	ld a, [hl]
 	and a, ACT_DIR_MASK
 	ld b, 0
@@ -101,6 +161,10 @@ act_move_forward:
 
 	ld hl, act_dir_vector
 	add hl, bc ; hl = direction vector
+	ld b, [hl] ; b = direction
+	
+	call act_apply_vec
+
 	ret
 	
 	; moves the actor back
diff --git a/src/levels.s b/src/levels.s
index 49a23c8..0e4161b 100644
--- a/src/levels.s
+++ b/src/levels.s
@@ -11,7 +11,7 @@
 l1:
 	mapdef MAP_F_DO_FULL_REDRAW, map_r_nop, 0, tile_banks_default, tile_id_table
 	.db 2, 0, 0, 0, 0, 0
-	.db 0, 0, 0, 0, 0, 0
+	.db 3, 0, 0, 0, 0, 0
 	.db 0, 0, 0, 0, 0, 0
 	.db 0, 0, 0, 0, 0, 0
 	.db 0, 0, 0, 0, 0, 0
diff --git a/src/player.s b/src/player.s
index fb4ac6e..869b5ab 100644
--- a/src/player.s
+++ b/src/player.s
@@ -77,6 +77,7 @@ player_handle_move:
 		ld hl, act_dir_forward
 		ld de, player
 		call act_can_move
+		ld de, player
 		call nz, act_move_forward
 @not_up:
 
@@ -86,6 +87,7 @@ player_handle_move:
 		ld hl, act_dir_back
 		ld de, player
 		call act_can_move
+		ld de, player
 		call nz, act_move_back
 @not_down: